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Number 4 / 2021
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DOI 10.35776/VST.2021.04.01
UDC 628.161.3:544.77.052.22
Gandurina L. V., Frog B. N., Giro Kristina
Clarification of turbid water with the use of Praestol 650 flocculant
Summary
The efficiency of the individual use of the cationic flocculant Praestol 650 for the purification of turbid water is considered, depending on the turbidity of the source water and the conditions of flocculation. It is shown that the priority parameters that determine the effectiveness of the individual use of the cationic flocculant Praestol 650 for the purification of turbid natural water are the intensity and duration of mixing in the flocculation chamber. With a duration of at least 20 min and an average gradient of mixing rate G = 340 s-1, the efficiency of turbidity reduction is 96% (final turbidity being 7 mg/l). A 96% efficiency of the non-ionic flocculant with a molecular weight of 5–7 million was determined in a suboptimal flocculation mode with a mixing period of 5 min and G = 65 s-1.
Key words
settling , turbidity , flocculation , cationic flocculant , water clarification , mixing rate gradient
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DOI 10.35776/VST.2021.04.03
UDC 628.35:661.5
Pukemo M. M., Koulakov A. A., Zheltukhin Roman
Features of hospital wastewater treatment
Summary
At high concentrations of nitrogen compounds and low concentrations of organic substances in wastewater, the process of denitrification does not proceed in full, resulting in a high concentration of nitrates in the effluent. The experience of using an extra substrate to supply the denitrified nitrate nitrogen with the required organic matter is described. Deep suppression of biocenosis at high concentrations of chlorine derivatives in raw wastewater was revealed. At a total chlorine concentration of 5.4–6.8 mg/l, neither biological treatment processes proceeded, nor a biofilm formed on the media surface. It is noted that the composition of the hospital wastewater is characterized by a low concentration of organic matter (BOD5 was on average 42.3 mg/l, COD – on average 128.9 mg/l) with a total nitrogen concentration of 43.4 mg/l. The effectiveness of using sucrose as a substrate for the denitrification of hospital wastewater has been experimentally confirmed. The sugar consumption was 0.17 kg/m3 at the ratio of BOD5/total nitrogen of 0.95 in the incoming wastewater.
Key words
treatment facilities , denitrification , hospital wastewater , extra substrate , sucrose
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DOI 10.35776/VST.2021.04.04
UDC 628.29:556.164
Primin Oleg, Vereshchagina Lidiia
Method for estimating the incoming flow of surface runoff in the urban storm sewer
Summary
According to the provisions of the Water Code of the Russian Federation No. 74-FZ and Federal Law No. 416-FZ «On Water Supply and Wastewater Disposal», all enterprises operating public wastewater disposal systems, including surface runoff drainage systems, shall, in accordance with the established procedure, keep a commercial record of the volume of wastewater received by the operated systems, as well as of the volume of wastewater discharged into water bodies. The method for accounting for the volume of surface runoff discharged into public systems of communities and into urban water bodies, as well as the specific features of applying the method with the use of calculations. It is shown that the implementation of justified methods for accounting for the volume of surface runoff discharged from urban territories into water bodies will ensure the reliability and legitimacy of the calculations of the volumes of received (removed) surface runoff in the process of the state monitoring of water bodies, determining the basis of charging for the negative environmental impact and setting tariffs for the customers using sewer network.
Key words
surface runoff , public storm sewer , drainage-river network , effluent outfall , commercial effluent discharge accounting
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DOI 10.35776/VST.2021.04.05
UDC 628.221
Volkov Sergei, Zhitenev A. I., Rublevskaya O. N., Kurganov Iu. A., Kostenko I. G., IGNATCHIK V. S., Ignatchik S. Iu., Kuznetsova N. V., Seniukovich Mikhail
Evaluation of the effectiveness of mechanisms for eliminating flooding of urbanized areas with surface runoff
Summary
Flooding of urbanized areas happens quite often, while, during periods of heavy rains, water rises to the surface flooding streets and basements. Flooding occurs for different reasons or due to their combination. The list of measures to reduce the flooding rate has been worked out in the world practice. These include measures aimed at reducing the runoff coefficient of drainage areas, as well as increasing the spare regulating capacities of the networks and sewers, etc. However, evaluating their effectiveness in the Russian Federation is complicated by the fact that the standard method of hydraulic calculation provides for taking into account the values of the periods of one-time excess of the calculated rainfall rates p that indicates the overflow rate in the networks. However, this method does not determine the rate pp of area flooding that results from the water spills. Through the example of St. Petersburg, a calculation method is presented for determining the average annual number of floods, as well as the results of evaluating the effectiveness of measures aimed at reducing them.
Key words
drainage area , surface runoff disposal system , climatic parameters , force of rain , rainfall duration , travel time , flooding
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DOI 10.35776/VST.2021.04.06
УДК 628.336.6:620.97:621.515
Bazhenov V. I., Ustiuzhanin A. V., Koroleva Ekaterina
Cogeneration plants to compensate for the needs of wastewater treatment facilities in energy resources
Summary
The relevance of the work is associated with increasing the efficiency of the energy resources use. Commissioning water and wastewater treatment facilities with cogeneration dates back to 2009: Mosvodokanal JSC (Kurianovskie and Lyuberetskie treatment facilities, power 10 MW each), Vodokanal JSC, Ivanovo (2.55 MW), Cherepovets Vodokanal MUE (2.4 MW). The life cycle cost was determined on the basis of the operating costs subject to the constraints of the conditions of self-sufficient projects. The operating costs included: gas, electricity, heat energy, costs of spare parts, lubricant, personnel, etc. The use of gas engine cogeneration units to compensate for the needs of the wastewater treatment plants with blower units is an economically viable measure in the Russian Federation. This serves as the basis for the use of cogeneration units in projects of wastewater treatment plants located close to the main gas pipelines. Optimistic and pessimistic scenarios for the development of this area depend on the choice of vodokanals to use thermal energy. The cost of 1 m3 of wastewater treatment can be reduced: by 0.894/0.44 rubles for the operating blower units (with 28% excess energy consumption due to wear); by 0.644/0.317 rubles for the advanced blower units; by 0.688/0.361 rubles for the advanced controlled blower units. The benefit from using cogeneration units is 53.3%/36% and 56.9%/41% for uncontrolled and controlled blower units, respectively. It makes sense to consider capital costs at the design stage that includes specific, object-oriented requests for the equipment manufacturer.
Key words
biogas , cogeneration , wastewater aeration , air-blowing house , alternative energy supply , natural gas , engineering-economic analysis
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DOI 10.35776/VST.2021.04.07
UDC 628.3:62-192
Yermolin Yu. A., Baranov L. A.
Specificity and methodological features of evaluating the reliability of sewer networks in large cities
Summary
The paper draws attention to the structural differences of two equivalent subsystems of a single infrastructure of a water supply and wastewater disposal system in a large city: a water supply subsystem and a wastewater disposal subsystem. It is stated that by now there is no unified established concept regarding the quantitative measure of the reliability of the sewer network. Based on the results of a review of modern domestic scientific and technical literature, three approaches to evaluating the reliability of municipal wastewater disposal systems are singled out and critically analyzed. The capabilities determined by the accepted assumptions are identified, and the areas of practical use of each of them are specified.
Key words
reliability , sewerage network , state graph , method of segmentation and equivalenting , Kolmogorov equations , «destruction and replication» scheme
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DOI 10.35776/VST.2021.04.08
UDC 628.144:532.542
Orlov V. А., Zotkin S. P.
Study of changes in the coefficient of hydraulic friction of materials of pressure pipes at different temperatures
Summary
Reducing the cost of electricity for the mechanical transportation of water through pressure pipelines by reducing the hydraulic resistance of the inner walls of the pipes is of current importance. This circumstance predetermines the need for appropriate hydraulic testing of alternative materials that can be used in the design and construction of pipeline systems. The aim of the study is to identify the nature of the change in the value of hydraulic friction depending on the temperature conditions of the transported water and the environment in certain ranges, with the subsequent possible control of the transportation process with a minimum of energy costs. The set goals are achieved by experimental computational and analytical approaches to determining the dynamics of changes in the hydraulic parameters of pipelines made of various materials. A comprehensive analysis of the experimental and calculated data obtained using patented automated systems for determining the coefficients of hydraulic friction for a polyethylene pipe and a pipe made of unplasticized polyvinylchloride, and the dynamics of changes in these coefficients depending on the temperature of the transported water and the temperature conditions of pipeline laying is presented.
Key words
pressure pipeline , hydraulic resistance , electrical energy consumption , temperature conditions , computerized calculations
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